JP2001280764A - Air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute a defrosting operation while continuing a heating operation so as to obtain excellent feeling of air conditioning even in the case of needing defrosting. SOLUTION: An air conditioning system comprises a compressor 120 driven by an engine 110 and coupled to refrigerant pipeline 130 of an indoor side heat exchanger 122 and an outdoor side heat exchanger 124 via a four-way valve 121, and a refrigerant pump 140, a bypass opening/closing valve 141 and a water heat exchanger 142 provided at a refrigerant pump bypass pipeline 132 connected at its one end side to a high-pressure liquid tube 131 of the refrigerant pipeline and connected at the other end side to the refrigerant pipeline 135 connected from the vale 121 to the exchanger 122. The system further comprises a defrosting bypass pipeline 150 for connecting a branch point C of the pipeline 132 to a branch point D of a low-pressure gas pipeline 134 to install a first defrost opening/closing valve 151 and a throttling mechanism 152, and a second defrost opening/closing valve 160 installed at the pipeline 135 connected from the valve 121 to a branch point A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for driving a compressor of a refrigerant by an internal combustion engine (engine).
In particular, the present invention relates to a gas heat pump type air conditioner that can simultaneously perform defrosting and heating operation of an outdoor heat exchanger.

[0002]

2. Description of the Related Art In recent years, an internal combustion engine that uses city gas (LNG) or LPG as a fuel as a drive source of a compressor for compressing a refrigerant has been used, and its exhaust heat has been used effectively to achieve a coefficient of performance (COP). Air conditioners of the gas heat pump type have been developed to improve the heating capacity at low outdoor temperatures. Such an air conditioner is configured to absorb heat from the air (outside air) on the low-pressure side of the refrigerant and at the same time recover exhaust heat of the engine. COP can be improved. The theoretical COP is a theoretical value when the efficiency of the compressor is 100%, and is expressed by the following formula: (theoretical COP) = (heating capacity) / (compressor power).

However, in the conventional configuration in which heat is absorbed from the air and exhaust heat on the low pressure side of the refrigerant, when the low pressure rises due to the recovery of the exhaust heat, the temperature difference between the refrigerant temperature and the outside air temperature becomes smaller, so that the amount of heat absorbed from the air is reduced. A problem arises in that the number of particles decreases. Accordingly, a gas heat pump type air conditioner has been proposed in which a refrigerant pump system for increasing the pressure of a liquid refrigerant is provided to recover exhaust heat of an engine, and exhaust heat recovery and heat absorption from air are separated. . With such a configuration, the amount of heat absorbed from the air can be reduced by the amount of exhaust heat recovered, so that the compressor can be operated at a low speed (low rotation speed) to greatly improve the COP. . That is, in this case, the denominator of the equation for obtaining the COP is the sum of the compressor power and the refrigerant pump power, but the power required for operating the refrigerant pump is considerably smaller than the power of the compressor, and Since the power of the compressor decreases in proportion to the number of revolutions, the power reduction due to the low-speed operation of the compressor has a great effect, and the denominator can be reduced, thereby improving the COP.

A gas heat pump type air conditioner equipped with the above-described refrigerant pump system will be briefly described with reference to FIG. The illustrated air conditioner is called a multi-system, and one outdoor unit 100 and a plurality (three in the illustrated example) of indoor units 101 are connected via a header 102 via a refrigerant pipe. I have.

[0005] Compressor 120 driven by engine 110
Is a four-way valve 121, an indoor heat exchanger 122, and an electronic expansion valve (hereinafter, indoor unit expansion valve) 1 which is a pressure reducing element for cooling operation.
23, an outdoor heat exchanger 124 and an electronic expansion valve (hereinafter referred to as an outdoor unit expansion valve) 125, which is a decompression element for heating operation, are connected via a refrigerant pipe 130, and circulate the refrigerant to change the state of the refrigeration cycle. To form a refrigerant circuit.
The four-way valve 121 performs a switching operation between a heating operation and a cooling operation, and can select one of a heating operation position indicated by a solid line and a cooling operation position indicated by a broken line in the drawing, and thereby the flow of the refrigerant in the refrigerant circuit. The direction is switched. In the drawing, reference numeral 126 denotes a receiver, 127 denotes an accumulator, and 128 denotes a check valve.

The refrigerant pump bypass line 132 branched from the high-pressure liquid pipe 131 of the refrigerant line 130 has a refrigerant pump 140 for increasing the pressure of the liquid refrigerant and a bypass on-off valve 14.
1 and a water heat exchanger 142 for introducing the engine cooling water of the engine 110. This water heat exchanger 142
Is connected to the cooling water pipe 113 of the engine 110 together with a radiator 111 for cooling the engine cooling water by exchanging heat with the atmosphere and an exhaust gas heat exchanger (hereinafter, exhaust gas heat exchange) 112 for heating the engine cooling water by the heat of the exhaust gas. In addition, it has a function of recovering exhaust heat of the engine cooling water and vaporizing the liquid refrigerant. The cooling water pipe 113 is provided with a cooling water circulating pump 114 and an open / close valve and a flow control valve (not shown) as appropriate.
Reference numeral 2 is used to promote the engine cooling water to rise to a predetermined temperature with the high-temperature exhaust gas immediately after the operation of the engine 110 is started.

Here, the flow of the refrigerant during the heating operation indicated by solid arrows in the drawing will be briefly described. The high-temperature and high-pressure gas refrigerant compressed by the compressor 120 is supplied to the four-way valve 12 at the heating position.
1 guides through the header 102 to the indoor heat exchanger 122. The gas refrigerant exchanges heat with indoor air to be condensed and liquefied, so that heat can be radiated to indoor air for heating. As a result, a high-temperature and high-pressure liquid refrigerant is formed, and the check valve 1
28, and flows through the high-pressure liquid pipe 131 in the order of the header 102 and the receiver 126. This liquid refrigerant is divided at the branch point B into the outdoor heat exchanger 124 side and the refrigerant pump 140 side.

The high-temperature and high-pressure liquid refrigerant flowing toward the outdoor heat exchanger 124 is reduced in pressure by the outdoor unit expansion valve 125 to become a low-temperature and low-pressure liquid refrigerant (mist).
24. In the outdoor heat exchanger 124, the low-temperature and low-pressure liquid refrigerant exchanges heat with the outside air and evaporates to become a low-temperature and low-pressure gas refrigerant. This gas refrigerant passes through the four-way valve 121 and the accumulator 127 and is sucked into the compressor 121 again. As a result, a refrigeration cycle is configured in which the indoor heat exchanger 122 is a condenser and the outdoor heat exchanger 124 is an evaporator.

The high-temperature and high-pressure liquid refrigerant flowing through the refrigerant pump bypass line 132 toward the refrigerant pump 140 is:
After being pressurized by the refrigerant pump 140, it is guided to the water heat exchanger 142, heated by hot water (engine cooling water) supplied from the engine 110, vaporized and vaporized, and becomes a high-temperature and high-pressure gas refrigerant. This gas refrigerant merges with the high-temperature and high-pressure gas refrigerant delivered from the compressor 120 at the branch point A, and the header 1
02, and is supplied to the indoor heat exchanger 122.

Next, the flow of the refrigerant during the cooling operation indicated by the dashed arrow in the drawing will be briefly described. The high-temperature and high-pressure gas refrigerant compressed by the compressor 120 is supplied to the four-way valve 12 in the cooling position.
The liquid is condensed and liquefied by being introduced into the outdoor heat exchanger 124 by means of 1 and exchanging heat with outside air. The refrigerant that has become a high-temperature and high-pressure liquid in this way passes through the check valve 128, and is further guided through the receiver 126 and the header 102 to the indoor unit expansion valve 123. In the indoor unit expansion valve 123, the high-temperature and high-pressure liquid refrigerant is reduced in pressure to become a low-temperature and low-pressure liquid refrigerant (mist). After this,
The low-temperature and low-pressure liquid refrigerant is sent to the indoor-side heat exchanger 122 and exchanges heat with indoor air. At this time, heat of vaporization is taken and the air is cooled to become a low-temperature and low-pressure gas refrigerant. This gas refrigerant is
It is sucked into the compressor 121 again through the four-way valve 121 and the accumulator 127. As a result, the indoor heat exchanger 1
A refrigeration cycle is configured in which 22 is an evaporator and the outdoor heat exchanger 124 is a condenser. In such a cooling operation, the operation of the refrigerant pump 140 is stopped, and the on-off valve 141 is closed.

[0011]

By the way, as described above, in the heat pump type air conditioner which performs the cooling operation and the heating operation by switching the flow direction of the refrigerant, especially in the heating operation when the outside air temperature is lowered, When the operation is continued, frost is formed on the surface of the outdoor heat exchanger 124 used as the evaporator, and there is a problem that the heat exchange (heating) ability is reduced. For this reason, in the conventional air conditioner, the temperature of the outdoor heat exchanger 124 and the outside air temperature are detected, and when it is determined that frost has occurred by map control or the like, it is necessary to perform the defrost operation for a predetermined time to dissolve the frost. was there.

In this defrost operation, the four-way valve 121 is switched from the heating position to the cooling position to perform the cooling operation. Therefore, since the outdoor heat exchanger 124 changes from an evaporator during the heating operation to a condenser during the cooling operation, the frosted outdoor heat exchanger 124 is supplied with a high-temperature and high-pressure gas refrigerant, The frost can be dissolved by the heat of condensation when the gas refrigerant condenses. However, since such a conventional defrost operation performs a cooling operation in a situation where a heating operation is required, the conditioned air blown into the room from the indoor unit becomes cold air, which is not preferable as an air conditioning feeling. .

Further, the outdoor heat exchanger 124 and the radiator 111 are arranged adjacent to each other, and their fins are integrated to prevent frost formation and improve the heating capacity by conducting heat from the radiator 111 having a high temperature. It is possible. However, in such a configuration, even during the cooling operation, the outdoor heat exchanger 124 functioning as a condenser is affected by the heat conduction as in the heating operation. For this reason, the high pressure in the refrigeration cycle increases, and as a result, a large driving force is required to drive the compressor 120, which causes a problem of deteriorating the COP.

The present invention has been made in view of the above circumstances, and in order to obtain an excellent air conditioning feeling even when defrosting is required, it is possible to perform a defrost operation while continuing a heating operation. The purpose of this is to provide an air conditioner that has been optimized.

[0015]

The present invention employs the following means in order to solve the above-mentioned problems. The air conditioner according to claim 1, wherein the compressor driven by the engine is connected to the refrigerant pipe of the indoor heat exchanger and the outdoor heat exchanger via a four-way valve, and the high-pressure liquid of the refrigerant pipe is connected to the compressor. A refrigerant pump is connected to a refrigerant pump bypass pipe having the other end connected to a high-pressure gas pipe through which a high-temperature and high-pressure gas refrigerant discharged from the compressor flows when one end is connected to a pipe and the four-way valve is in a heating position. An air conditioner provided with a bypass on-off valve and an exhaust heat recovery heat exchanger of the engine, wherein the refrigerant pump bypass line has an exhaust heat recovery heat exchanger outlet side and a low pressure gas line of the refrigerant channel. A defrost bypass pipe having a first defrost opening / closing valve and a throttle mechanism connected therebetween and a refrigerant pipe provided between the four-way valve and the other end side connection part of the refrigerant pump bypass pipe. 2 Defrost on-off valve It is characterized in. In this case, as the exhaust heat recovery heat exchanger, a water heat exchanger that recovers exhaust heat from cooling water of the engine to a refrigerant or an exhaust gas heat exchanger that recovers exhaust heat to refrigerant from the exhaust gas of the engine is used. It is preferred to use.

According to such an air conditioner, when the refrigerant pump is operated with the four-way valve in the cooling position, the first defrost on / off valve opened, and the second defrost on / off valve closed during the defrost operation, the outdoor heat can be reduced. Simultaneously forms a refrigeration cycle using an exchanger as a condenser and an exhaust heat recovery heat exchanger as an evaporator, and a refrigeration cycle using an indoor heat exchanger as a condenser and an exhaust heat recovery heat exchanger as an evaporator. can do.
For this reason, the outdoor heat exchanger functioning as a condenser has a defrost operation in which defrost is performed by the heat of condensation, and the indoor heat exchanger also functioning as a condenser has a heating operation in which the indoor air is heated by the heat of condensation. , Can be implemented simultaneously.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an air conditioner according to the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 100 denotes an outdoor unit, and the outdoor unit 100 includes a header 102 and a refrigerant pipe 1.
A plurality (three in the illustrated example) of indoor unit units 101 are connected via the unit 30. On the other hand, the outdoor unit 1
00 is a lower machine room 100A and an upper heat exchanger room 1
00B.

In the lower machine room 100A, a gas engine 110, a compressor 120 driven by the gas engine 110, a refrigerant pump 140, a water heat exchanger 142, and an exhaust gas heat exchanger 11 are provided.
2 etc. are installed. The radiator 111 and the outdoor heat exchanger 1 are provided in the upper heat exchanger chamber 100B.
24 and an outdoor unit fan are installed. Compressor 1
The outlet of 20 is provided by a high-pressure gas line 133, and the inlet is provided by a low-pressure gas line 134, respectively.
Is connected to The other two connection ports of the four-way valve 121 are connected to the header 102 by refrigerant pipes 135 and 136.
And the outdoor heat exchanger 124. Header 1
02 and each indoor unit 101 are connected by two refrigerant pipes 137 and 138, respectively.
01, the indoor heat exchanger 122 and the indoor unit expansion valve 12
3. The check valve 128 and the indoor unit fan are installed.
Note that the indoor unit expansion valve 123 and the check valve 128 are arranged in parallel in the refrigerant pipe 138, and the refrigerant flows through one of them in accordance with the operation mode.

The high pressure liquid pipe 131 connecting the header 102 and the outdoor heat exchanger 124 is provided with a receiver 126, an outdoor unit expansion valve 125, and a check valve 128. The receiver 126 has a function of separating gas-liquid of the condensed refrigerant and temporarily storing the liquid refrigerant.
Further, the outdoor unit expansion valve 125 and the check valve 128 are arranged in parallel, and the refrigerant flows through one of them in accordance with the operation mode. In addition, the outdoor heat exchanger 124 is
The refrigerant pipe 136 is also connected to the four-way valve 121. Further, a refrigerant pump bypass pipe 132 is provided in the middle of the high-pressure liquid pipe 131 at a branch point B between the receiver 126 and the outdoor unit expansion valve 125 in the illustrated example. This refrigerant pump bypass line 1
The other end 32 is connected to a refrigerant pipe 135 that connects the four-way valve 121 and the header 102, and the other end is shown as a branch point A.

In the refrigerant pump bypass line 132, a refrigerant pump 140, a bypass on-off valve 14
1 and a water heat exchanger 142 are provided. The refrigerant pump 140 pressurizes the high-temperature and high-pressure liquid refrigerant at the branch point A where the high-temperature and high-pressure gas refrigerant flows so that the gas refrigerant flowing through the refrigerant pump bypass pipe 132 can join. The bypass opening / closing valve 141 may be provided on the upstream side of the refrigerant pump 141 (on the branch point B side).

The water heat exchanger 142 is connected to a cooling water line 11 which is a circulation line of engine cooling water for cooling the engine 110.
3 is connected. The water heat exchanger 142 has a function of heating and evaporating the high-temperature and high-pressure liquid refrigerant pressurized by the refrigerant pump 140 with engine cooling water (hot water) and supplying it to the branch point A as a high-temperature and high-pressure gas refrigerant. are doing. The cooling water pipe 113 to which the water heat exchanger 142 is connected is a pipe that cools the engine 110 and guides the high-temperature engine cooling water to the radiator 111 for cooling. An engine cooling water pump 114 is provided and the exhaust gas heat exchange 112 is also connected. The exhaust gas heat exchange 112 exchanges heat between the exhaust gas and the engine cooling water. For example, if necessary, the exhaust heat of the engine 110 is recovered from the high-temperature exhaust gas to promote the temperature rise of the engine cooling water. However, it is used for the purpose of shortening the idling operation time. The cooling water pipe 113 is provided with an open / close valve and a flow control valve (not shown) as appropriate, so that known flow switching and flow control can be performed.

In addition to the above-described configuration, a branch point C and one end are connected to the refrigerant pump bypass line 132 on the outlet side of the water heat exchanger 142, and a low-pressure gas line between the four-way valve 121 and the accumulator 127 is provided. At 134, the branch point D
A defrost bypass line 150 is provided, to which the other end is connected. In this defrost bypass line 150,
A first defrost opening / closing valve 151 and a capillary tube 152 as a throttle mechanism are provided in this order from the branch point C side. Here, the first defrost opening / closing valve 151 is provided for the purpose of selectively opening / closing the defrost bypass line 150 depending on the operation mode. The capillary tube 152 is provided with a high-temperature high-pressure high-pressure gas vaporized by the water heat exchanger 142. This is provided for the purpose of reducing the pressure of the gas refrigerant and supplying it to the low-pressure gas pipeline 134. By setting the position of the branch point D upstream of the accumulator 127, the gas refrigerant supplied from the defrost bypass pipe 150 can be supplied to the compressor 120 after gas-liquid separation, The trouble of the compressor 120 caused by the suction of the liquid refrigerant can be prevented.

Further, a second defrost opening / closing valve 160 is provided in the refrigerant pipe 135 between the four-way valve 121 and the branch point A. The second defrost opening / closing valve 160 is provided for the purpose of preventing the refrigerant from flowing back to the four-way valve 121 during a defrost operation described later. The second
The position where the defrost opening / closing valve 160 is installed cannot be replaced with a check valve because the flow direction of the refrigerant differs between the heating operation and the cooling operation.

In the following, the operation of the air conditioner having the above-described structure will be described with the opening and closing of valves and the flow of refrigerant in each operation mode. Figure 2 shows the state of heating operation first
And will be described. In this heating operation mode, as shown in FIG.
41 is open, the first defrost on-off valve 151 is closed, the second defrost on-off valve 160 is open, the indoor unit expansion valve 123 is fully closed,
The outdoor unit expansion valve 125 is in an opening control in accordance with the heating load, and the refrigerant pump 140 is in an operating state.

The high-temperature and high-pressure gas refrigerant compressed by the compressor 120 is guided to the header 102 through the four-way valve 121 and the refrigerant pipe 135. In the indoor unit 101, the high-temperature and high-pressure gas refrigerant first passes through the indoor heat exchanger 122 and exchanges heat with the air introduced by the indoor unit fan. At this time, the high-temperature and high-pressure gas refrigerant condenses and heats the air by the heat of condensation, so that the air that has passed through the indoor heat exchanger 122 becomes hot air. On the other hand, the high-temperature and high-pressure liquid refrigerant condensed by passing through the indoor heat exchanger 122 reaches the header 102 through the refrigerant line 138 and the check valve 128, and further passes through the high-pressure liquid tube 131 and the receiver 126. It is led to a branch point B.

At the branch point B, the high-temperature and high-pressure liquid refrigerant is
Flow toward outdoor heat exchanger 124 and refrigerant pump 140
And diverge into The liquid refrigerant heading to the outdoor heat exchanger 124 is decompressed when passing through an outdoor unit expansion valve 125 whose opening degree is controlled according to the heating load, and becomes a low-temperature low-pressure liquid refrigerant to the outdoor heat exchanger 124. Supplied. This liquid refrigerant exchanges heat with the outside air introduced by the outdoor unit fan and evaporates to become a low-temperature and low-pressure gas refrigerant, which becomes the refrigerant line 136, the four-way valve 121, the low-pressure gas line 134, and the accumulator 12.
The flow returns to the compressor 120 via. Therefore, a refrigeration cycle is formed in which the indoor heat exchanger 122 is a condenser and the outdoor heat exchanger 124 is an evaporator, and the indoor unit 101 provided with the indoor heat exchanger 122 functions as a heater.

On the other hand, the flow of the liquid refrigerant from the branch point B to the refrigerant pump 140 through the refrigerant pump bypass line 132 is boosted in the refrigerant pump 140 and is guided to the water heat exchanger 142 through the bypass on-off valve 141. I will In the water heat exchanger 142, the high-temperature and high-pressure liquid refrigerant recovers and evaporates the exhaust heat of the engine cooling water to become a high-temperature and high-pressure gas refrigerant.
This gas refrigerant is guided to the branch point A through the refrigerant pump bypass pipe 132, merges with the high-temperature and high-pressure gas refrigerant sent from the compressor 120, and thereafter flows toward the header 102 and the indoor unit 101. In the heating operation mode, the first defrost opening / closing valve 151 is closed, so that the high-temperature and high-pressure gas refrigerant does not flow into the defrost bypass pipe 150. Accordingly, in this case, since the indoor heat exchanger 122 functions as a condenser and the water heat exchanger 142 functions as an evaporator, the exhaust heat of the engine 110 is recovered by the water heat exchanger 142. Heating capacity can be improved. In addition, the outdoor heat exchanger 12 has an amount corresponding to the amount of exhaust heat recovered by the water heat exchanger 142.
4, since the amount of heat absorbed from the outside air can be reduced, the operating speed of the compressor 120 can be reduced to improve the COP.

Next, the state of the cooling operation will be described with reference to FIG. In this cooling operation mode, as shown in FIG.
The four-way valve 121 is in the cooling position, the bypass on-off valve 141 is closed,
The first defrost opening / closing valve 151 is closed, the second defrost opening / closing valve 160 is opened, the indoor unit expansion valve 123 is controlled in an opening degree according to the cooling load, the outdoor unit expansion valve 125 is fully closed, and the refrigerant pump 14
0 indicates that the operation is stopped.

The high-temperature and high-pressure gas refrigerant compressed by the compressor 120 is guided to the outdoor heat exchanger 124 through the four-way valve 121 and the refrigerant pipe 136. In the outdoor heat exchanger 124, the high-temperature and high-pressure gas refrigerant is first supplied to the outdoor heat exchanger 124.
And heat exchange with the outside air introduced by the outdoor unit fan. At this time, the high-temperature and high-pressure gas refrigerant condenses into a high-temperature and high-pressure liquid refrigerant, reaches the header 102 through the high-pressure liquid pipe 131, the check valve 128 and the receiver 126, and furthermore, the refrigerant pipe 138 and the indoor unit expansion valve It is led to the indoor heat exchanger 122 through 123. The high-temperature and high-pressure liquid refrigerant passing through the indoor unit expansion valve 123 is decompressed, and is supplied to the indoor heat exchanger 122 as a low-temperature and low-pressure liquid refrigerant.

In the indoor heat exchanger 122, the low-temperature and low-pressure liquid refrigerant exchanges heat with the indoor air introduced by the indoor unit fan and is vaporized to become a low-temperature and low-pressure gas refrigerant. At this time, the indoor air is deprived of heat of vaporization and cooled, and is blown into the room as cold air. The low-temperature low-pressure gaseous refrigerant is thus supplied to the refrigerant line 137, the header 102, and the refrigerant line 13
5. Return to the compressor 120 via the four-way valve 121, the low-pressure gas line 134 and the accumulator 127. Accordingly, a refrigeration cycle is formed in which the outdoor heat exchanger 124 is a condenser and the indoor heat exchanger 122 is an evaporator.
The indoor unit 101 provided with 2 functions as a cooler. During the cooling operation, the refrigerant pump 14
Since the operation at 0 is stopped, the refrigerant does not flow through the refrigerant pump bypass line 132 and the defrost bypass line 150.

Finally, the state of the defrost operation will be described with reference to FIG. In this defrost operation mode, as shown in FIG.
41 is open, the first defrost on-off valve 151 is open, the second defrost on-off valve 160 is closed, the indoor unit expansion valve 123 is fully closed,
The outdoor unit expansion valve 125 is fully closed, and the refrigerant pump 140 is in an operating state. That is, in this defrost operation mode, when it is determined that frost has formed on the outdoor heat exchanger 124 in the heating operation mode, the four-way valve 121 is switched to the cooling position to reverse the flow of the refrigerant, and the first defrost on-off valve 1
The outdoor unit expansion valve 1 switches the open / close state of the first and second defrost opening / closing valves 16 and further reverses the flow direction of the refrigerant.
25 is switched from the opening control to the fully closed state.

In this way, the high-temperature and high-pressure gas refrigerant compressed by the compressor 120 passes through the four-way valve 121 and the refrigerant pipe 136 in the same manner as in the cooling operation.
Guided to 24. In the outdoor heat exchanger 124, the high-temperature and high-pressure gas refrigerant first passes through the outdoor heat exchanger 124, and exchanges heat with the outside air introduced by the outdoor unit fan. At this time, the high-temperature and high-pressure gas refrigerant is condensed to become a high-temperature and high-pressure liquid refrigerant, so that the frost of the outdoor heat exchanger 124 can be melted by the heat of condensation. The high-temperature and high-pressure liquid refrigerant condensed in the outdoor heat exchanger 124 is guided to the branch point B through the high-pressure liquid pipe 131 and the check valve 128.

At the branch point B, the outdoor heat exchanger 1
The high-temperature and high-pressure liquid refrigerant flowing from the heat exchanger 24 joins the high-temperature and high-pressure liquid refrigerant flowing from the indoor heat exchanger 122 through a path described later, and flows toward the refrigerant pump 140 through the refrigerant pump bypass line 132. . This flow is pressurized in the refrigerant pump 140 and guided to the water heat exchanger 142 through the bypass on-off valve 141. In the water heat exchanger 142, the high-temperature and high-pressure liquid refrigerant recovers and evaporates the exhaust heat of the engine cooling water to become a high-temperature and high-pressure gas refrigerant.

This gas refrigerant is guided to the branch point C through the refrigerant pump bypass line 132 and is directly guided to the branch point A, and the first defrost opening / closing valve 1 in the open state.
The refrigerant is diverted into the refrigerant flowing through the defrost bypass pipe 150 through the refrigerant passage 51. The high-temperature and high-pressure gas refrigerant flowing to the branch point A flows toward the header 102 and the indoor unit 101 through the refrigerant pipe 135. At this time, since the second defrost opening / closing valve 160 is closed, the refrigerant does not flow to the four-way valve 121 side or the refrigerant flows from the four-way valve 121 side. In the indoor unit 101, similarly to the normal heating operation, the high-temperature and high-pressure gas refrigerant first passes through the indoor heat exchanger 122 and exchanges heat with the air introduced by the indoor unit fan. At this time, the high-temperature and high-pressure gas refrigerant condenses and heats the air by the heat of condensation, so that the air that has passed through the indoor heat exchanger 122 becomes hot air.

On the other hand, the high-temperature and high-pressure liquid refrigerant condensed by passing through the indoor heat exchanger 122 reaches the header 102 through the refrigerant line 138 and the check valve 128, and further flows into the high-pressure liquid tube 131 and the receiver 126. Through to the junction B. At this branch point B, the high-temperature and high-pressure liquid refrigerant flowing from the indoor heat exchanger 122 merges with the high-temperature and high-pressure liquid refrigerant flowing from the outer heat exchanger 124 as described above. The refrigerant flows and is pressurized by the refrigerant pump 140, and thereafter circulates in the same refrigerant pipe. As a result, the indoor heat exchanger 122 is used as a condenser, and the water heat exchanger 1 is used as a condenser.
A refrigeration cycle of a heating operation using the evaporator 42 is formed.

On the other hand, through the first defrost opening / closing valve 151 in the open state, the defrost bypass pipe 150
The high-temperature and high-pressure liquid refrigerant flowing through the capillary tube 1
The refrigerant is decompressed at 52 and becomes a low-temperature low-pressure gas refrigerant.
Merges into the low-pressure gas pipeline 134 at. Although this gas refrigerant is in a gas-liquid two-phase state, the gas-liquid is separated by passing through the accumulator 127, and only the low-temperature and low-pressure gas refrigerant is sucked into the compressor 120. Thereafter, it is similarly compressed by the compressor 120 and sent out to the outdoor heat exchanger 124.

As described above, during the defrost operation, the refrigeration cycle of the heating operation in which the indoor heat exchanger 122 is a condenser and the water heat exchanger 142 is an evaporator, and the outdoor heat exchanger 124 is a condenser. In addition, since the refrigeration cycle of the defrost operation using the water heat exchanger 142 as the evaporator can be formed at the same time, the defrosting of the outdoor heat exchanger 124 is performed while the heating operation by the indoor unit 101 is continued. Can be. In other words, the refrigerant compressed by the compressor 120 forms a refrigeration cycle using the outdoor heat exchanger 124 as a condenser and the water heat exchanger 142 as an evaporator, and forms frost on the outdoor heat exchanger 124. The defrost operation to defrost the frost is performed, and at the same time, the refrigerant pressurized by the refrigerant pump 140 forms a refrigeration cycle using the indoor heat exchanger 122 as a condenser and the water heat exchanger 142 as an evaporator, The heating operation by the indoor unit 101 can be performed.

Therefore, even when the outside air temperature is low and frost is formed on the outdoor heat exchanger 124, there is no need to temporarily perform the cooling operation to perform defrosting as in the related art, and therefore, heating is required. In this situation, no cool air is blown from the indoor unit 101, and a sufficient heating capacity can be obtained and a good air conditioning feeling can be provided. In addition, by collecting the exhaust heat of the engine 110, the defrost of the outdoor heat exchanger 124 can be efficiently performed, and the time required for the defrost operation can be reduced. The above-described defrost operation is performed for a predetermined time by a timer or the like, and then returned to the normal heating operation.

In the embodiments described so far, the water heat exchanger 142 for recovering the exhaust heat from the engine cooling water is used as the exhaust heat recovery heat exchanger for recovering the exhaust heat of the engine 110. The air conditioner of the present invention is not limited to this. For example, a first modification described below with reference to FIG. 6 is possible. In the first modification, an exhaust gas heat exchanger 112A connected to recover exhaust heat from exhaust gas of the engine 110 is used as an exhaust heat recovery heat exchanger that recovers exhaust heat of the engine 110. This exhaust gas heat exchange 112A vaporizes a high-temperature and high-pressure liquid refrigerant with exhaust gas, and differs in that a refrigerant pump bypass pipe 132A branched from a branch point B is connected to the exhaust gas heat exchange 112A.

FIG. 6 shows a state of the defrost operation. In this defrost operation mode, the four-way valve 121 is in the cooling position and the bypass opening / closing valve 1 is the same as in the above-described embodiment.
41 is open, the first defrost on-off valve 151 is open, the second defrost on-off valve 160 is closed, the indoor unit expansion valve 123 is fully closed,
The outdoor unit expansion valve 125 is fully closed, and the refrigerant pump 140 is in an operating state.

In this manner, the high-temperature and high-pressure gas refrigerant compressed by the compressor 120 passes through the four-way valve 121 and the refrigerant pipe 136 in the same manner as in the cooling operation.
Guided to 24. In the outdoor heat exchanger 124, the high-temperature and high-pressure gas refrigerant first passes through the outdoor heat exchanger 124, and exchanges heat with the outside air introduced by the outdoor unit fan. At this time, the high-temperature and high-pressure gas refrigerant is condensed to become a high-temperature and high-pressure liquid refrigerant, so that the frost of the outdoor heat exchanger 124 can be melted by the heat of condensation. The high-temperature and high-pressure liquid refrigerant condensed in the outdoor heat exchanger 124 is guided to the branch point B through the high-pressure liquid pipe 131 and the check valve 128.

At this branch point B, the outdoor heat exchanger 1
The high-temperature and high-pressure liquid refrigerant flowing from the heat exchanger 24 merges with the high-temperature and high-pressure liquid refrigerant flowing from the indoor heat exchanger 122 through a path described later, and flows toward the refrigerant pump 140 through the refrigerant pump bypass pipe 132A. . This flow is pressurized in the refrigerant pump 140 and guided to the exhaust gas heat exchange 112A through the bypass on-off valve 141. Exhaust gas heat exchange 112
In A, the high-temperature and high-pressure liquid refrigerant recovers and vaporizes the exhaust heat of the exhaust gas discharged from the engine 110, and becomes a high-temperature and high-pressure gas refrigerant.

This gas refrigerant is guided to the branch point C through the refrigerant pump bypass line 132A, and is directly changed to the branch point A.
And the refrigerant flowing through the first defrost opening / closing valve 151 in the open state and flowing through the defrost bypass pipe 150. The high-temperature and high-pressure gas refrigerant flowing to the branch point A flows toward the header 102 and the indoor unit 101 through the refrigerant pipe 135. At this time, since the second defrost opening / closing valve 160 is closed, the refrigerant does not flow to the four-way valve 121 side or the refrigerant flows from the four-way valve 121 side. Indoor unit 101
Then, similarly to the normal heating operation, the high-temperature and high-pressure gas refrigerant first passes through the indoor heat exchanger 122 and exchanges heat with the air introduced by the indoor unit fan. At this time, the high-temperature and high-pressure gas refrigerant condenses and heats the air by the heat of condensation, so that the air that has passed through the indoor heat exchanger 122 becomes hot air.

On the other hand, the high-temperature and high-pressure liquid refrigerant condensed by passing through the indoor heat exchanger 122 reaches the header 102 through the refrigerant line 138 and the check valve 128, and further passes through the high-pressure liquid tube 131 and the receiver 126. Through to the junction B. At this branch point B, the high-temperature and high-pressure liquid refrigerant flowing from the indoor heat exchanger 122 merges with the high-temperature and high-pressure liquid refrigerant flowing from the outdoor heat exchanger 124 as described above, and the refrigerant pump bypass 132A The refrigerant flows and is pressurized by the refrigerant pump 140, and thereafter circulates in the same refrigerant pipe. As a result, the indoor heat exchanger 122 is used as a condenser, and the exhaust gas heat exchange 1
A refrigeration cycle of a heating operation using 12A as an evaporator is formed.

On the other hand, through the first defrost opening / closing valve 151 in the open state, the defrost bypass line 150 is opened.
The high-temperature and high-pressure liquid refrigerant flowing through the capillary tube 1
The refrigerant is decompressed at 52 and becomes a low-temperature low-pressure gas refrigerant.
Merges into the low-pressure gas pipeline 134 at. Although this gas refrigerant is in a gas-liquid two-phase state, the gas-liquid is separated by passing through the accumulator 127, and only the low-temperature and low-pressure gas refrigerant is sucked into the compressor 120. Thereafter, it is similarly compressed by the compressor 120 and sent out to the outdoor heat exchanger 124.

As described above, during the defrost operation, the refrigeration cycle of the heating operation using the indoor heat exchanger 122 as a condenser and the exhaust gas heat exchanger 112A as an evaporator, the outdoor heat exchanger 124 as a condenser, and Exhaust gas heat exchange 112A
Can be formed at the same time as the evaporator, so that the outdoor unit heat exchanger 124 can be defrosted while the heating operation by the indoor unit 101 is continued.

Even with such a configuration, when the outside air temperature is low and frost forms on the outdoor heat exchanger 124, there is no need to temporarily perform the cooling operation to perform defrosting as in the conventional case, and therefore, Indoor unit 101 in situations where
No cooling air is blown from the air, so that a sufficient heating capacity can be obtained and a good air conditioning feeling can be provided. Also, by collecting the exhaust heat of the engine 110,
Defrosting of the outdoor heat exchanger 124 can be efficiently performed, and the time required for the defrost operation can be reduced. Note that, except for the above-described defrost operation, that is, for the heating operation and the cooling operation, since the water heat exchanger 142 of the above-described embodiment is replaced with the exhaust gas heat exchange 112A, the substantial refrigerant flow and state change are the same. Here, the detailed description is omitted.

In the embodiment described so far, the refrigerant pump 140 is disposed upstream of the water heat exchanger 142 for recovering exhaust heat from the engine cooling water (on the branch point B side) to increase the pressure of the liquid refrigerant. However, as in the second modification shown in FIG. 7, the refrigerant pump 1 is located downstream of the water heat exchanger 142 (on the branch point C side).
It is good also as composition which arranges 40A. In this case, the refrigerant pump 140A increases the pressure of the vaporized gas refrigerant that has passed through the water heat exchanger 142. However, even with such a configuration, the refrigerant pump 140A does not require a defrost operation, and is similar to the above-described embodiments. The operation and effect of the invention can be obtained.

[0049]

As described above, according to the air conditioner of the present invention, a simple defrost bypass line having a first defrost opening / closing valve and a throttle mechanism and a second defrost opening / closing valve are added. With the configuration, the refrigerant compressed by the compressor forms a refrigeration cycle in which the outdoor heat exchanger is used as a condenser and the exhaust heat recovery heat exchanger is used as an evaporator, and frost formed on the outdoor heat exchanger is formed. The defrost operation to be performed is performed, and at the same time, the refrigerant pressurized by the refrigerant pump forms a refrigeration cycle in which the indoor heat exchanger is used as a condenser and the exhaust heat recovery heat exchanger is used as an evaporator. A heating operation can be performed.

Therefore, even if frost forms in the heating operation at a low outside air temperature, defrosting can be efficiently performed while the heating operation is continued, so that cool air is not blown out from the indoor unit and the air conditioning feeling is reduced. It can be greatly improved. Also, to recover and defrost the exhaust heat of the engine,
This has the effect of preventing a decrease in the heating capacity and shortening the time of the defrost operation.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a gas heat pump type air conditioner of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a flow of a refrigerant when the air-conditioning apparatus illustrated in FIG. 1 is in a heating operation state.

3 is a schematic configuration diagram illustrating a flow of a refrigerant when the air-conditioning apparatus illustrated in FIG. 1 is in a cooling operation state.

4 is a schematic configuration diagram illustrating a flow of a refrigerant when the air-conditioning apparatus illustrated in FIG. 1 is in a defrost operation state.

FIG. 5 is a diagram collectively showing open / close positions and states of main valves and the like in the air-conditioning apparatus shown in FIG. 1 for each operation mode.

FIG. 6 is a schematic configuration diagram showing a first modification of the gas heat pump type air conditioner shown in FIG.

FIG. 7 is a schematic configuration diagram showing a second modification of the gas heat pump type air conditioner shown in FIG.

FIG. 8 is a diagram of a schematic configuration example according to a conventional gas heat pump type air conditioner.

[Explanation of symbols]

Reference Signs List 100 outdoor unit 101 indoor unit 110 engine 112, 112A exhaust gas heat exchanger (exhaust gas heat exchange) 120 compressor 121 four-way valve 122 indoor heat exchanger 123 indoor unit expansion valve (electronic expansion valve) 124 outdoor heat exchange Unit 125 Outdoor unit expansion valve (electronic expansion valve) 130 Refrigerant line 131 High pressure liquid line 132, 132A Refrigerant pump bypass line 133 High pressure gas line 134 Low pressure gas line 140, 140A Refrigerant pump 141 Bypass opening / closing valve 142 Water heat exchange Container 150 Defrost bypass line 151 First defrost on-off valve 152 Capillary tube (throttle mechanism) 160 Second defrost on-off valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeki Ozeki 1 Nagoya Laboratory, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi, Japan Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. 3-1, Cho-cho Mitsubishi Heavy Industries, Ltd. Air Conditioner Works (72) Inventor Takeshi Yokoyama 1-5-20 Kaigan, Minato-ku, Tokyo Tokyo Gas Co., Ltd. (72) Inventor Taku Nakamura 1-5, Kaigan, Minato-ku, Tokyo No. 20 Tokyo Gas Co., Ltd.

Claims (3)

[Claims] 1. A compressor driven by an engine is connected to a refrigerant pipe of an indoor heat exchanger and an outdoor heat exchanger via a four-way valve, and one end is connected to a high-pressure liquid pipe of the refrigerant pipe. And when the four-way valve is in the heating position, the other end is connected to a high-pressure gas line through which a high-temperature and high-pressure gas refrigerant discharged from the compressor flows. In an air conditioner provided with an exhaust heat recovery heat exchanger of an engine, a first connection is established by connecting an exhaust heat recovery heat exchanger outlet side of the refrigerant pump bypass pipe and a low pressure gas pipe of the refrigerant flow path. A defrost bypass line provided with a defrost opening / closing valve and a throttle mechanism; and a second defrost opening / closing valve provided in the refrigerant line between the four-way valve and the other end side connection portion of the refrigerant pump bypass line. The sky characterized by comprising Conditioning apparatus. 2. The air conditioner according to claim 1, wherein the exhaust heat recovery heat exchanger is a water heat exchanger that recovers exhaust heat from cooling water of the engine to a refrigerant. 3. The air conditioner according to claim 1, wherein the exhaust heat recovery heat exchanger is an exhaust gas heat exchanger that recovers exhaust heat from exhaust gas of the engine to a refrigerant.